Standards for WLAN technologies have been developed as Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards. IEEE 802.11a and 802.11b use an unlicensed band at 2.4 GHz or 5 GHz. IEEE 802.11b provides a transfer rate of 11 Mbps and IEEE 802.11a provides a transfer rate of 54 Mbps. IEEE 802.11g provides a transfer rate of 54 Mbps using Orthogonal frequency division multiplexing (OFDM) at 2.4 GHz. IEEE 802.11n provides a transfer rate of 300 Mbps for 4 spatial streams using multiple input multiple output-OFDM (MIMO-OFDM). IEEE 802.11n supports a channel bandwidth of up to 40 MHz and, in this case, provides a transfer rate of 600 Mbps.
An IEEE 802.11af standard for defining operations of unlicensed devices in a TV white space (TVWS) band is currently under development. In order for an unlicensed device to operate in a white space band, it is required to acquire information regarding available channels which are not used by a licensed device.
Hereinafter, a Mesh Network will be described.
FIG. 1 is a view illustrating a concept of a mesh network.
The mesh network means a network in which each node transmits and receives data thereof and, in addition, relays data for the other nodes. That is, in the mesh network, nodes may cooperate for data transmission in the network.
As shown in FIG. 1, the mesh network may include a plurality of Mesh Points (MPs). That is, the MPs constitute a multi-hop wireless network.
An MP providing an infrastructure BSS may be referred to a Mesh Access Point (MAP). In the following description, it is assumed that the MAP is included in the MPs.